Detection of pregnancy in ewe lambs by A-mode ultrasound.

The objectives of the study were to determine the time required to learn the detection of pregnancy using a technique of A-mode ultrasound and then to test the method on a commercial flock of 181 ewe lambs. Nine-and-a-half hours were spent learning the technique. The trial on the commercial flock showed that of 113 ewe lambs which produced offspring 98 were correctly predicted as pregnant and 15 were wrongly predicted as not pregnant. Of 68 ewe lambs which did not produce offspring 47 were correctly predicted as not pregnant and 21 were wrongly predicted as pregnant. The practicalities of the technique and the consequences of the test errors are discussed.

Observations on the mammary glands of culled ewes at the time of slaughter.

Gross abnormalities of the mammary glands of 1650 culled ewes were recorded. Clinically obvious lesions were detected in 211 (12.8 per cent) of udders; 77 per cent of lesions were abscesses. A generalised calcification of the whole of a gland was observed in 23 udders. It is concluded that abnormalities of the udder are an important reason for the culling ewes. The assessment of the cost-effectiveness of measures to reduce the incidence of mastitis would be worthwhile.